In recent years, with the rapid popularization of onboard navigation and positioning, GPS/Beidou navigation device installed on an automobile has already been widely used. Many automobiles, especially commercial automobiles, may need two navigation devices, one of which is an onboard host for the usual navigation and positioning, the other of which is a remote automobile networking for achieving functions of long-range tracking and positioning of the automobiles. Two GPS/Beidou antennas are thus required accordingly. The current general practice is either to install two GPS/Beidou antennas or to install one antenna in the automobile with a 3 dB power divider connected. However, both of the above two methods have the following problems:
1. A hardware cost may certainly be increased if two antennas are used. In addition, the installation is very inconvenient in case the installation space and location of onboard antenna are limited.
2. Assumed that a 3 dB power divider is used, a 3 dB degradation of the overall system noise may be occurred if the power divider is placed between the amplifier and the antenna; and two paths may be required to work normally at the same time if the power divider is located at an output of the amplifier. If one path is abnormal (open circuit or short circuit), the other path may not work normally, resulting in a very poor overall compatibility of the device.